Test Overview
Test Methodology

Next Generation Sequencing

Test Usage

Oncogenic mutations within the KIT gene occur in a subset of melanomas, most frequently in those of mucosal (~20%) and acral (~15%) types, and less commonly in those from cutaneous and conjunctival sites. These KIT mutations are predicted to be activating, and are similar to those found in imatinib-responsive cancers of other types. Testing for KIT mutation in melanoma may aid in identifying patients who might benefit from therapies such as imatinib that target activated KIT. This DNA test is performed by targeted next-generation sequencing (NGS) and will detect KIT mutations within the sequenced regions of exons 8, 9, 11, 13 and 17 (see Additional Information below for specific regions sequenced). Specimens should contain an adequate proportion of neoplastic nuclei (>10%) in the areas to be extracted to ensure mutation detection.

Reference Range *

Interpretive report provided.

* Reference ranges may change over time. Please refer to the original patient report when evaluating results.

Test Limitations

This test will only detect the mutations within specific gene regions (See Additional Information below for specific information). This test may fail to detect mutations below the limit of detection of this assay (approximately 5%). Discordant results are rarely observed between metastatic and primary tumors. This test cannot distinguish between somatic and germline alterations. Additional testing may be required if there is concern for a clinically relevant germline alteration. The clinical implications of the findings as indicated in the test report may change based on evolution of the scientific literature.

Test Details
Days Set Up
Monday - Thursday
Analytic Time

5-12 days

Soft Order Code
MEL
MiChart Code
KIT Mutation for Melanoma
Synonyms
  • MEL
  • KIT Mutation Detection for Imatinib Therapy
  • c-KIT Mutation
  • KIT Exon 11 13 17 Mutation
  • KIT Mutation Detection - Melanoma
Laboratory
Molecular Diagnostics
Section
Molecular Diagnostics
Specimen Requirements
Collection Instructions

For formalin-fixed, paraffin-embedded tissue, a block containing an area with a high percentage of neoplastic cells (for micro-/macro-dissection) is preferred. Unstained, UNBAKED slides (5-8, 10-micron slides; 10-15 if few neoplastic cells are present) with associated H&E stained slide are also acceptable. Decalcified tissue or other fixatives will be accepted and the assay attempted, however these may result in failed testing due to degraded nucleic acid. Both blocks and slides should be stored at room temperature. A Diff-Quik or Papanicolaou stained aspirate smear (preferable containing a high percentage and overall amount of neoplastic cells) is also acceptable. Store at room temperature.

Alternate Specimen
For exhausted formalin-fixed, paraffin-embedded blocks, the original Hematoxylin and Eosin stained slide(s) may be extracted at the discretion of the Molecular Diagnostics Laboratory Director. The extraction process will result in destruction of the slide(s). A digital image of the slide(s) must be collected prior to extraction and retained for a minimum of 10 years from the specimen collection date. Previously extracted DNA may be accepted; however, the extracting laboratory must take responsibility for ensuring that viable, neoplastic cells comprise at least 20% of cellularity within the extracted sample.

Normal Volume
Formalin-fixed, paraffin-embedded tissue; Diff-Quik stained aspirate smear, Papanicolaou stained aspirate smear. Extracted DNA is also acceptable if extracted in a CLIA certified laboratory.
Additional Information

Updated on: 12/06/2017
By ordering this test the clinician acknowledges that informed consent has been obtained from the patient as required by applicable state or federal laws and the ordering clinician has authorization from the patient permitting MLabs to report the test results to the ordering clinician. Test includes pathologist interpretation of results billed as a separate additional charge. This test is not available without interpretation.

Billing
CPT Code
81272, 88381-TC
Fee Code
NA058, NA037
Pro Fee CPT
G0452-26, 88381-26
NY State Approved
No